1. Technical Field
This invention relates to devices for sensing fluid flow within a pipe utilizing ultrasonic sensors on pipe walls in general, and to the same which are enclosed to protect said ultrasonic sensors from harsh environments in particular.
2. Background Information
Clamp-on ultrasonic flow meters are a desirable tool for determining characteristics of a fluid flow traveling through a pipe. Ultrasonic flow meters typically include a plurality of ultrasonic sensors, each having a transmitter and a receiver. In some sensor configurations, ultrasonic signals emitted from the transmitters travel through the immediate pipe wall, the fluid flow disposed within the pipe, and through the opposite pipe wall where they are sensed by the receiver portion. The received signal is processed to determine information such as flow velocity, volumetric flow rate, water cut, etc.
Clamp-on fluid flow meters are often used in environments where the signal to noise ratio of the signals sensed by the receivers makes it difficult to accurately distinguish the portion of the signal bearing information relating to the fluid flow, from that which does not; i.e., “noise”. Clamp-on fluid flow meters are also sometimes used in extreme environments; e.g., under water environments or those having combustible materials. There is considerable advantage, therefore, in any apparatus or methodology that facilitates the sensing process in a way that improves the signal to noise ratio, and also advantage for any mounting apparatus that allows a clamp-on meter to be used in a harsh environment.